The present invention is directed to concentrated light duty all-purpose liquid cleaning compositions, more particularly to concentrated light duty all-purpose spray and wipe liquid cleaning compositions which can be diluted by the end user to the end user's preferred strength. A method for using such compositions is also disclosed.
The compositions of the present invention and the method of use relate to the specialized class of concentrated cleaning products which are designed to be used as is or diluted by the end user to a preferred strength for the particular job at hand. Such concentrated cleaning compositions can be applied from any type of hand-operated sprayer or from a bucket dilution, and more preferably can be applied from a hand-held sprayer which dilutes the product in a ratio acceptable to the end user such as that shown in U.S. Pat. No. 5,152,461 and patent application Ser. No. 07/865,001; both of which are hereby incorporated by reference.
There has long been a desire to produce concentrated cleaners for consumer use. Concentrated cleaners provide high strength cleaning for difficult soils, economical solutions when diluted and minimize packaging and transportation costs. In some cleaning applications, such as heavy duty laundry applications, concentrated formulas based on high surfactant levels are known in the art and have been prepared successfully with the use of suitable surfactants and hydrotropes. Likewise, powder formulations with high concentrations are known in the art and are typically made through the use of agglomeration or similar technology.
Similarly, light duty all-purpose cleaners are known in the art. For example, U.S. Pat. No. 5,230,823 discloses a light duty liquid cleaning composition using extremely pure alkyl ethoxy carboxylates and optionally includes a cosurfactant and a suds booster. U.S. Pat. No. 4,627,931 discloses a diluted and concentrated composition for hard surface cleaning which includes a nonionic surfactant and an organic solvent in combination with a builder. U.S. Pat. No. 3,882,038 discloses a diluted and concentrated composition containing a surfactant, a builder and glycol ether solvents. However, highly concentrated all-purpose spray and wipe cleaners which can be diluted by the end user to the end user's preferred strength are not known in the art. This is due in part to the need in a consumer product of several characteristics such as dilutability, wettability of surfaces and soils, no streaking, quick evaporation, good cleaning characteristics and the ability to meet safety standards for household products. The typical approach to these all-purpose spray and wipe cleaners is to make the product in low concentrated form with the use of moderate levels of water-soluble solvents in combination with low levels of cosurfactants and builders.
Problems often occur when attempting to produce an all-purpose spray and wipe cleaner in highly concentrated form. Solvents which evaporate quickly typically have low flash points. On increasing the concentration of these solvents, compositions with unacceptably low formula flash points are produced. Also, typically, solvents which exhibit high soil solvency tend to have lower evaporation rates which can result in products which are difficult for the consumer to use and can leave streaks on the surfaces being cleaned. Therefore, above certain solvent concentrations, it has been difficult to formulate a concentrated product which meets consumer acceptability.
One approach to the aforementioned problem has been to use builder salts in a formula with low concentrations of surfactants and solvents to thereby enhance the performance of the surfactants and solvents. This approach gives good cleaning, and because the salts are not volatile, they do not lower the flash point of the composition. However, streaking is often inherent in these compositions with builder salts and evaporation rates are slower. Builders also have significant environmental liabilities.
Another approach known in the art has been the use of solvent blends, combining higher and lower volatility solvents, to enhance evaporation and raise flash points. However, solvent blends with both high evaporation rates and high flash points often exhibit instabilities in product formulations containing surfactants and water. In particular, high solvent all-purpose cleaning systems typically suffer from a lack of homogeneity, thus requiring the consumer to extensively agitate the product prior to using in order to obtain an equal dispersion of materials.